Sensitizer for blue-sensitive emulsions



"United States PatentOflice 3,480,434 Patented Nov. 25, 1969 3,480,434 SENSITIZER FOR BLUE-SENSITIVE EMULSIONS 1 Ernest R. Hanna, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Filed Nov. 26, 1965, Ser. No. 513,145

. Int. Cl. G03c 1/76, 7/16 U.S. Cl. 96-74 4 Claims ABSTRACT OF THE DISCLOSURE In photographic elements comprising an opaque support having coated thereon a blue sensitive silver halide emulsion layer containing yellow dye former, and green and red sensitive silver halide emulsions coated thereover containing, respectively, magneta and cyan dye former, a sulfo substituted merocyanine dye is incorporated in the blue sensitive emulsion layer.

This invention relates to photography. One aspect of this invention relates to improved blue-sensitized photographic silver halide emulsions and photographic elements containing such emulsions.

In the conventional sensitivity arrangement of multilayer photographic elements, the red-sensitive layer is coated adjacent to the support and this is followed in order by the green-sensitive emulsion layer and then the blue-sensitive emulsion layer. It is customary to form a cyan-dye image in the red-sensitive layer, a magenta-dye image in the green-sensitive layer and a yellow-dye image in the blue-sensitive layer. A different sensitivity arrange' ment may be utilized in which either the red-sensitive layer or the green-sensitive layer is coated outermost for the purpose of improving definition. The definition of the resulting color picture is determined to a large extent by the cyan and magenta dye images, and the over-all definition can be improved by arranging the three emulsion layers so that the layer containing the cyan or magenta dye image is outermost and the layer containing the yellow dye image is adjacent to the support or farthest from the exposure source. This arrangement is described, for example, in Baker U.S. Patent 1,867,301 and Tarbin U.S. Patent 1,871,479.

When this inverted order of sensitivity is utilized, it is necessary to employ a blue-sensitive emulsion layer, i.e., the emulson layer closest to the support, which has a higher blue-light speed than would be required if the bluesensitive emulsion layer were outermost. Conventional methods of increasing the sensitivity of this layer have not been satisfactory. The use of silver halide emulsions of higher inherent speed has reduced color image definition. Higher speeds obtained by modifications in chemical sensitization techinques have resulted in poor keeping stability as evidenced by loss of speed during incubation and/ or increase in undesirable stain.

One object of this invention is to provide novel bluesensitive photographic emulsions containing a color forming coupler and blue sensitizing dye, which emulsions are characterized by high speed, low fog and low stain. Another object of this invention is to provide novel photographic elements comprising a support having coated thereon a photographic emulsion containing color forming couplers and a blue sensitizing dye. A further object of this invention is to provide novel photographic elements suitable for recording multicolor images which comprises a support having coated thereon an emulsion having good speed, low fog and reduced tendency to stain, and which contains a blue sensitizing dye and an incorporated coupler which reacts with oxidized color developer to form yellow dye, said layer having coated thereover separate overlying emulsion layers, one layer comprising an emulsion sensitive to green radiation and containing a compound which forms magenta colored dye with oxidized color developer and the other layer comprising a redsensitive emulsion layer containing a compound which forms cyan dye with oxidized color developer. Still another object is to provide a process for obtaining multicolor images in an exposed photographic element comprising separate red, green and blue sensitive emulsion layers containing, respectively, cyan, magenta and yellow color formers, the blue sensitive emulsion layer being closest to the support and containing blue sensitizing dye, which includes developing said elements in a color forming developer containing a primary amino group. Other objects of this invention will be apparent from this disclosure and the appended claims.

In accordance with this invention, novel photographic emulsions, elements and processes are provided which feature the combination, in silver halide emulsions of (1) compounds capable of forming dye upon reaction with oxidized color developer, and (2) certain blue sensitizing sulfo-substituted merocyanine dyes, which are defined more fully below. This combination provides emulsions which have an unexpected increase in speed, an unexpected reduction in fog and low stain. These advantages are unexpected since, when the corresponding carboxy substituted merocyanine dyes are incorporated in normal developing out emulsions which do not contain color former, the carboxy substituted dyes provide higher speed and lower fog than the sulfo substituted merocyanine dyes employed herein. It appears that there may be some interaction between the sulfo substituted dyes employed in this invention and color forming compounds which results in the higher speed and lower fog than would be expected.

In one embodiment of this invention, novel photographic emulsions are provided containing a color forming coupler and a blue sensitizing sulfo substituted merocyanine dye of the type defined below, which emulsions are characterized by high speed and low fog.

In another embodiment of this invention, novel photographic elements are provided comprising a support having coated thereon a photographic emulsion containing a color forming coupler, and a blue sensitizing sulfo substituted merocyanine dye of the type defined below.

In another embodiment of this invention, novel photographic elements suitable for recording multicolor images are provided which comprise a support, preferably opaque, having coated thereon an emulsion containing a blue sensitizing sulfo substituted merocyanine dye of the type defined below, and an incorporated coupler capable of reaction with oxidized color developer to form yellow dye, said layer having coated thereover separate overlying emulsion layers, one layer comprising an emulsion sensitive to green radiation and containing a compound capable of forming magenta colored dye with oxidized color developer and the other layer having a red-sensitive emulsion layer containing a compound capable of forming cyan dye with oxidized color developer.

In still another embodiment of this invention, a process is provided for obtaining multicolor images in an exposed photographic element comprising a support having coated thereon separate red, green and blue sensitive emulsion layers containing, respectively, cyan, magenta and yellow color formers, the blue-sensitive emulsion layer being closest to the support and containing a blue sensitizing dye, which includes developing said element with a color forming developer containing a primary amino group.

The blue sensitizing sulfo substituted spectral sensitizing dyes employed in this invention have the following general formula:

wherein R and R each represents an alkyl radical (i.e., an alkyl group substituted or unsubstituted) e.g., methyl. ethyl, n-butyl, isobutyl, sulfoethyl, sulfobutyl, allyl, B- ethoxyethyl, B-hydroxyethyl, ,B-acetoxyethyl, carbethoxy methyl, B-phenylethyl or benzyl, or R and R each represents an aryl group, e.g., phenyl, L represents a methine group substituted or unsubstituted, n represents a positive integer of from 1 to 2, m represents a positive integer of from 1 to 2, d represents a positive integer of from 1 to'2, Q represents an oxygen atom, a sulfur atom or a group of the formula where R represents an alkyl radical (i.e., an alkyl group substituted or unsubstituted), or an aryl group, Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing atoms in the heterocyclic ring, e.g., a rhodanine nucleus, a 2-thi0-2,4(3,5)- oxazoledione nucleus, a 2-thiohydantoin nucleus, a 5- pyrazolone nucleus, etc., said heterocyclic nucleus containing at least one group selected from the group consisting of sulfo (SO H) alkyl and sulfoalkoxyalkyl, such as sulfoethyl, sulfopropyl, sulfobutyl, and groups having the formula and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, and preferably including a hetero N, Se, 0 or S atom, e.g., a nucleus of the benzothiazole series, a nucleus of the benzoxazole series, a nucleus of the benzoselenazole series, a nucleus of the B-naphthothiazole series, a nucleus of the ,B-naphthothiazole series, a nucleus of the a-naphthoxazole series, a nucleus of the p-naphthoxazole series, a nucleus of the a-naphthoselenazole series, a nucleus of the fl-naphthoselenazole series, a nucleus of the thiazoline series, a nucleus of the simple thiazole series (e.g., 4-methylthia zole, 4-phenylthiazole, 4-(2-thienyl)-thiazole, etc.), a nucleus of the simple selenazole series (e.g., 4-methylselenazole, 4-phenylselenazole, etc.) a nucleus of the simple oxazole series (e.g., 4-methyloxazole, 4-phenylthiazole, etc.), a nucleus of the quinoline series, a nucleus of the pyridine series, a nucleus of the 3,3-dialkylindolenine, etc. The sulfoalkyl and sulfoalkoxyalkyl groups preferably contain a relatively small number of carbon atoms to retain good solubility of the dye. It is generally desirable to use less than a total of 10 carbon atoms in the alkyl or alkoxyalkyl groups. Sulfoalkyl groups containing 1 to 4 carbon atoms and sulfoalkoxyalkyl groups having from 4 to 10 carbon atoms are preferred. Similarly, the alkyl radical substitueuts referred to above should not contain too high a number of carbon atoms. Good results are obtained with alkyl groups having less than about 8, and preferably from 1 to 4 carbon atoms.

An especially useful class of spectral sensitizers for the novel emulsions, elements and processes of the invention is represented by the following formula:

4 R-N L=L).. I o=o'o=o wherein R, L, n and Q have the values recited above. A preferred class of spectral sensitizers in accordance with the invention has the following formula:

wherein R, Z, L, n and Q have the meanings given above, and Q represents a sulfoalkyl group or a sulfoalkoxyalkyl group. As used herein, the term sulfo group refers to the sulfonic acid group itself and includes the water soluble salts thereof, including alkali metal salts (e.g., sodium, potassium, etc), ammonium salts (i.e., ammonium or organic ammonium, such as triethylammonium, pyridinium, triethanolammonium, etc.), etc.

A large number of sulfoalkyl dyes useful herein are specifically described in US. Patent 2,493,748. This patent discloses a number of specific carboxy alkyl dyes. Corresponding dyes which contain sulfoalkyl groups rather than carboxy alkyl groups are useful in this invention.

The sensitizing dyes employed herein are blue sensitizers. Preferably, these dyes impart no sensitivity to the emulsion beyond about 540 m However, in multicolor elements Where the blue sensitive layer is closest to the support, a suitable filter, such as a magenta, blue or blueviolet colored filter, may be employed over the blue sensitive layer and below the red and green sensitive layers. When such an arrangement is used, the dyes in the blue sensitive layer may sensitize in the blue region and on into the green region, such as up to about 600 or 620* m The filter in such instances eliminates any undesirable sensitizing to green (or red) radiation in the blue record layer. Hence, this invention is especially applicable to photographic elements where the emulsion layer in accordance with the invention is sensitive to blue radiation, but substantially insensitive to radiation beyond about 540 Inn.

This invention will be further illustrated by the following examples.

EXAMPLE 1 To two ditferent portions of the same batch of a gelatin-silver chlorobromoiodide photographic emulsion containing a coupler for the yellow image of the type described in McCrossen US. Patent 2,875,057, issued Feb. 24, 1959, are added 87 mg. of Dye 1* per silver mole, in one case, and 87 mg. of Dye II** per silver mole in the other case.

The emulsions are then coated on a paper support, chill-set and dried. Each of the series of coated emulsions are then exposed in an intensity scale sensitometer using 3000 K.500 watt illumination from a projection incandescent lamp. The exposed emulsions are then processed for 12 minutes in a developer having the following composition:

Water liter 1.0 Benzyl alcohol cc. 12.6 Sodium hexametaphosphate (Calgon) grams 2.0 Sodium sulfite, anhydrous do 2.1 Sodium carbonate monohydrate do 26.8 Sodium bicarbonate do 2.9 Potassium bromide do 0.48 Sodium chloride do 0.7 Hydroxylamine sulfate do 2.1 Color developer do 4.2

(pH at 75 F. 9.96)

tamino N ethyl N (B methanesulfonamidoethyl)-mtoluidine sesquisulfate monohydrate.

The developed coatings are then immersed in a stop bath for about 2 minutes. The stop bath has the following composition:

Water liter 1.0 Glacial acetic acid cc 17.0 Sodium sulfite, anhydrous grams 20.0

The coatings are then fixed for 2 minutes in a bath having the following composition:

. 1 The coatings are then washed in running water at about 73 to 77 F. for 2 minutes. The paper coatings are then treated for 4 minutes at 73 to 77 F. In a bleach bath having the following composition:

Water liter 1.0 Sodium nitrate grams 30.00 Potassium ferricyanide do 15.00 Potassium bromide do 4.80 Boric acid do 5.00 Borax do 0.69

The paper coatings are then washed in running water at 73 to 77 F. for 2 minutes and then fixed for 2 minutes in a hardener-fixing bath having the following composition:

Water liter 1.0 Glacial acetic acid cc 12.00 Sodium zirconyl sulfate (Zircontan-N) grams 0.38 Sodium bisulfite do 15.00 Sodium thiosulfate do 150.00 Sodium citrate do 1.73 Boric acid do 5.00- Potassium alum, granular do 24.00 Sodium hydroxide, granular do 7.00 Zinc sulfate monohydrate do 5.00'

The paper coatings are then washed in running water at 73 to 77 F. for 8 minutes and then treated for 3 minutes in a hardening bath at 73 to 77 F., the bath having the following composition:

The prints are then allowed to dry in the air or in a conventional drier.

The speeds of the coatings obtained above are then read on a reflection densitometer which reads the curves of monochromatic density as a function of exposure. The relative speed figures are given in the following table:

*Dye I-3 carboxymethyl 5-(3-ethyl-2-(3H)-benzothiazolylidene)-rhodanine Prepared as described in Example 1 of Brooker et al. U.S. Patent 2,493,748, issued Jan. 10, 1950.

**Dye H--3 fi sulfoethyl-5-(3'ethyl-2(3H)-benzothiazolylidene) -rhodanine Prepared as described in Example 2 of Brooker et al. U.S. Patent 2,493,748.

7 day incubation Fresh test 120 F./50% RH Rel. Rel. Feature speed Dmin speed Dmin Emu1sion+Dye I 09 100 18 Emulsion+Dye II 09 138 10 Example 2 Two samples of the following basic multilayer element are coated.

The multilayer element comprises a support having coated thereon a gelatin-silver chlorobromoiodide emulsion sensitized to the blue region of the spectrum as hereinafter described and contains a coupler for the yellow image of the type described in McCrossen et al. U.S. Patent 2,875,057, issued Feb. 24, 1959. The blue-sensitive layer also containsconventional emulsion addenda, such as an antistain agent (e.g., 2-n-octadecyl-5-(2-sulfotert.butyl) hydroquinone potassium salt, etc.),/etc. Coated over the blue-sensitive layer is a gelatin interlayer containing dioctyl hydroquinone. Over this gelatin interlayer is coated an ordinary gelatino-silver-chlorobromide egmulsion which is green-sensitive and contains a coupler for the magneta image, such as one of the couplers described in Loria et al. U.S. Patent 2,600,788 dated June 17, 1952. The couplers are dispersed in a conventional coupler solvent, such as tricresylphosphate. The green-sensitive emulsion layer also contains an antistain agent, such as dioctylhydroquinone. The green-sensitive emulsion layer also contains a green light absorbing dye.

Over the green-sensitive layer is coated an ordinary gelatin layer containing an ultraviolet absorbing compound, such as one of the compounds described in Sawdey U.S. Patent 2,739,888, dated Mar. 27, 1956. Also, the gelatin filter layer contains dioctylhydroquinone dispersed in a solvent, such as tricresylphosphate. Over the gelatin filter layer is coated an ordinary gelatino-silver-chlorobromide emulsion which is red-sensitive. This red-sensitive emulsion contains a coupler for the cyan image, such as one of the couplers described in Fierke U.S. Patent 2,801,171, dated July 30, 1957, the couplers being dispersed in a conventional solvent, such as dibutyl phthalate. The red-sensitive emulsion also contains an antistain agent, such as dioctylhydroquinone, and a red light absorbing dye of the type described in Saunders and Wilson U.S. application Ser. No. 541,059, filed Oct. 17, 1955, now U.S. Patent 2,865,752, issued Dec. 23, 1958. Over the redsensitive layer is coated an ordinary gelatin protective layer.

The two samples differ only in that one contains 87 mg. of Dye I per silver mole as the blue sensitizer whereas the other sample contains 87 mg, of Dye II per silver mole as the blue sensitizer. After exposure and processing of the two samples, in the manner described in Example 1, the following data are obtained:

7 EXAMPLE 3 Two monochrome coatings similar to those described in Example 1 are prepared. When these two coatings are exposed and processed as described in Example 1, the

Two samples are prepared and tested as in Example 2 except 3 carboxymethyl 5 [(3 methyl 2 (3)- thiazolinylidene) ethylidene[ 2 thio 2,4 (3,5)- oxazoledione is employed instead of Dye I and a dye having the following structure:

is employed instead of Dye II. Essentially the same results are obtained.

\ N-CHzCHaOCHgCHOHz NCH;4CHO onlomornonzsosu Results similar to those of Example 4 are obtained.

As noted above, this invention is quite unobvious in view of the fact that when closely related merocyanine dyes containing carboxyalkyl groups are incorporated in conventional developing out emulsions which do not contain color former, higher speed is obtained than when the corresponding sulfoalkyl substituted merocyanine dyes employed in the novel emulsions, elements and processes of the invention are incorporated in similar emulsions. For example, when Dyes I and II are incorporated in equal, sensitizing concentrations in separate portions of a conventional color coupler free developing out gelatin silver chlorobromide (95% chloride, 5% bromide) emulsions, and the emulsions are coated on supports, dried exposed and developed for 5 minutes in Kodak Developer DK-SO, Dye I produces a higher speed and lower fog than Dye II, as shown in the following table.

Speed Fog Dye I Dye II Similar results are obtained when the carboxyalkyl substituted dye used in Example 4 is substituted for Dye I, and when the sulfoalkyl substituted dyes of Examples 4, 5, 6 and 7 are substituted for Dye II. Therefore, it is highly suprising to find that when the sulfoalkyl dyes employed herein are used to sensitize color coupler containing silver halide developing out emulsions, a higher speed and lower fog is obtained than when the corresponding carboxyalkyl dyes are used.

The advantages of this invention are realized when any color coupler is present in the emulsion. The useful compounds are those capable of reacting with the oxidation products of a color developer (as described below) to form a yellow dye. Especially useful are coupler compounds for forming yellow dye images. A particularly useful class of coupler compounds for forming the yellow dye image have the general structure wherein R represents an alkyl group of from 1 to 20 carbon atoms and either one of the groups X and Y represents a hydrogen atom and the other represents an acylamido group. Specific coupler of this type, all useful in the present invention, are described in US. Patent 2,875,057. Other yellow forming couplers useful in the invention are described in US. Patents 2,521,908; 2,706,684; 2,455,169; 2,694,703; 2,455,170; 2,453,661; and French Patent 1,291,110. Generally, the preferred yellow-forming couplers are those containing an open chain reactive methylene group.

In the development of photographic products containing the sensitizers in accordance with the invention, any color-forming developer containing a primary amino group may be used. These include developers having two primary amino groups substituted or having substituents in the ring, such as the alkyl phenylene diamines. These compounds are usually used in the salt form, such as the hydrochloride or the sulfate which are more stable than the amines themselves. The suitable compounds are diethyl-p phenylene-diamine hydrochloride, monomethyl-pphenylenediamine hydrochloride, dimethyl-p-phenylenediamine hydrochloride and 2-amino-5-diethylaminotoluene hydrochloride. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these developers have an unsubstituted amino group which enables the oxidation products of the developer to couple with the color-forming compounds to form a dye image.

My preferred sensitizing dyes can be employed in silver halide emulsions in which the carrier or vehicle is gelatin or a hydrophilic colloid other than gelatin, such as, for example, albumin, agar-agar, gum arabic, alginic acid, etc., or a hydrophilic resin such as polyvinyl alcohol, polyvinyl pyrolidone, a cellulose ether, a partially hydrolyzed cellulose acetate, etc., which has no deleterious effect upon the light-sensitive silver halide. The blue sensitizers of this invention can be employed in the combinations of the invention in various concentrations, depending upon the particular emulsion utilized, the concentration of silver halide, the particular results desired, etc. The optimum concentration of the sensitizing dye can be determined in a manner well known to those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a different concentration of the sensitizing dye. Especially good results are obtained at concentrations of from about 5 to about mg. dye per liter of flowable emulsion.

The methods of incorporating sensitizing dyes in silver halide emulsions are also well known to those skilled in the art, and these known techniques are employed in dispersing the subject dyes in the emulsions. The dyes can be directly dispersed in the emulsion, or they can first be dissolved in some convenient solvent, such as pyridine, methyl alcohol, acetone, etc. (or mixtures of such solvents), or diluted with water in some instances, and added to the emulsion in the form .of these solutions. The dyes are dispersed in the finished emulsions and should be uniformly distributed throughout the emul sions before the emulsions are coated on a suitable support, e.g., paper, cellulose ester film, polyester film, polyolefin coated paper, such as electron bombarded polyethylene coated paper, polycarbonate -film and the like. In some instances it may be desirable to heat the spectrally sensitized emulsion for a few minutes before coating on the support. The details of such coating techniques are well known to those skilled in the art.

In most cases, it is convenient to add the sensitizing dye to the emulsion before the coupler dispersion is added. The color formers (couplers) are incorporated in the emulsion in the customary manner, e.g., by adding a dispersion of the coupler in a water-insoluble but waterpermeable material to the emulsion, or by adding a dispersion of the alkali-metal salt of the coupler in water. When employing dispersions of couplers in the aforesaid crystalloidal materials, the coupler which has been mixed with the high boiling organic crystalloidal material to produce an oil-like mixture can be dispersed in water or gelatin solution or in any aqueous binder of colloidal character which is miscible with the silver halide emulsion. The dispersion can be effected with the aid of a homogenizer, colloid mill or the like, and the dispersions can be stabilized by the addition of emulsifying agents such as those of the well-known higher fatty alcohol sulfate type. The dispersion may also be formed by dispersing a solution of coupler and crystalloidal material in a solvent of low boiling point such as butyl acetate with water or gelatin solution, and subsequently, removing the low-boiling solvent by evaporation. Here also an emulsifying agent can be used. It is important that the mixture of coupler and crystalloidal material be a liquid at ordinary temperatures, so that liquid particles are formed when the mixture of coupler and crystalloidal material is emulsified in water and mixed with the emulsion, the particles retaining the coupler in solution, yet being readily penetrated by the photographic developing solution and other processing baths.

My invention is directed primarily to the ordinarily employed silver halide developing out emulsions, e.g., gelatin-silver-chloride, -chlorobromide, -chilorobromoiodide, -iodochloride, -bromide and -bromoiodide developing out emulsions. These ordinarily employed silver halide developing-out emulsions are emulsions which form surface latent images (see British Patent 581,772, issued Oct. 24, 1946). However, silver halide emulsions which form latent image mostly inside the silver halide grains (see British Patent 581,772 supra) can also be employed in the practice of my invention.

The emulsions may be chemically sensitized by any of the accepted procedures. They may be digested with naturally active gelatin, or sulfur compounds may be added such as those described in Sheppard US. Patents 1,574,944 and 1,623,499 and Sheppard and Brigham US. Patent 2,410,689.

The emulsions may also be treated with salts of the noble metals such as ruthenium, rhodium, palladium, iridium and platinum, all of which belong to Group VIII of the periodic table of the elements and have an atomic weight greater than 100. Representative compounds are ammonia chloropalladate, potassium chloroplatinate and sodium chloropalladite, which are used for sensitizing in amounts below that which produces any substantial fog inhibition, as described by Smith and Trivelli in US. Patent 2,448,060, and as antifoggants in higher amounts as described in Trivelli and Smith US. Patents 2,566,245 and 2,566,263.

The emulsions may also be chemically sensitized with gold salts as described in Waller and Dodd US. Patent 2,399,083 or stabilized with gold salts as described in Damschroder US. Patent 2,597,856 and Yutzy and Leermakers US. Patent 2,597,915. Suitable compounds are potassium chloroaurite, potassium aurithiocyanate, potassium chloroaurate, auric trichloride and 2-aurosulfobenzothiazole methochloride. Combinations of these sensitizers, stabilizers, coating aids, etc., may be utilized, if desired.

Although the invention has been described in considerable detail with particular reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be effected Within the spirit and scope of the invention as described hereinabove, and as defined in the appended claims.

I claim:

1. A photographic element comprising an opaque support having coated thereon a silver halide developing out emulsion layer containing a compound which reacts with oxidized aromatic primary amino developer to form yellow dye, said compound having the following formula:

wherein R represents an alkyl group of from 1 to 20 carbon atoms and either one of the groups X and Y represents a hydrogen atom and the other represents an acylamido groups, and said emulsion containing a spectral sensitizing concentration of the dye 3-fi-sulfoethyl-5- (3 ethyl 2(3H)-benzothiazolylidene)-rhodanine; said layer having coated thereover, in the following order, separate, overlying light sensitive silver halide emulsion layers, the first overlying light sensitive emulsion layer being sensitive to green radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form a magenta dye, and the second overlying light sensitive emulsion layer being sensitive to red radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form cyan dye.

2. A photographic element comprising an opaque support having coated thereon a first silver halide developing out emulsion layer containing a compound which reacts with oxidized aromatic primary amino developer to form yellow dye, said emulsion being spectrally sensitized to blue radiation with a sensitizing dye having the following general formula:

wherein R and R each represents a member selected from the class consisting of an alkyl group and an aryl group, L represents a methine group; d, m and n each represents a positive integer of from 1 to 2; Q represents the nonmetallic atoms necessary to complete a heterocyclic nucleus having 5 atoms in the heterocyclic ring and containing a substituent selected from the class consisting of a sulfoalkyl group, a sulfoalkoxyalkyl group and the salt form of said groups; Q represents a member selected from the group consisting of an oxygen atom, a sulfur atom, and a group of the formula:

I -N-R3 wherein R represents a member selected from the class consisting of an alkyl group and an aryl group; and, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring; said first emulsion layer having coated thereover, in the following order, separate, overlying light sensitive silver halide emulsion layers, the first overlying light sensitive emulsion layer being sensitive to green radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form a magenta dye, and the second overlying light sensitive emulsion layer being sensitive to red radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form cyan dye.

3. A photographic element comprising an opaque support having coated thereon a first silver halide developing out emulsion layer containing a compound which reacts with oxidized aromatic primary amino developer to form yellow dye, said coupler containing an open chain reactive methylene group, and said emulsion being spectrally sensitized with a sensitizing dye having the following general formula:

wherein R represents a member selected from the glass consisting of an alkyl group and an aryl group, L represents a methine group; n represents a positive integer of from 1 to 2; Q represents the non-metallic atoms necessary to complete a heterocyclic nucleus having 5 atoms in the heterocyclic ring and containing a substituent selected from the class consisting of a sulfoalkyl group, a sulfoalkoxyalkyl group and the salt form of said groups; and, Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring; said first emulsion layer having coated thereover, in the following order, separate, overlying light sensitive silver halide emulsion layers, the first overlying light sensitive emulsion layer being sensitive to green radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form a magenta dye, and the second overlying light sensitive emulsion layer being sensitive to red radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form cyan dye.

4. A photographic element comprising an opaque support having coated thereon a first silver halide developing out emulsion layer containing a compound which reacts with oxidized aromatic primary amino developer to form yellow dye, said compound having the following formula:

I OR

wherein R represents an alkyl group of from 1 to 20 carbon atoms and either one of the groups X and Y repre sents a hydrogen atom and the other represents an acylamido group; said emulsion being spectrally sensitized to blue radiation with a sensitizing dye having the following general formula:

,----z---- O=C NQ2 l 'I(L=L)n 1o=o o=s wherein R represents a member selected from the class consisting of an alkyl group and an aryl group; L represents a methine group; n represents a positive integer of 1 to 2; Q represents a member selected from the group consisting of an oxygen atom, a sulfur atom, and a group of the formula:

wherein R represents a member selected from the class consisting of an alkyl group and an aryl group; Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring; and Q represents a substituent selected from the class consisting of sulfoalkyl groups containing from 1 to 4 carbon atoms, sulfoalkoxyalkyl groups containing from 4 to 10 carbon atoms, and the alkali metal and ammonium salts of said sulfo groups; said first layer having coated thereover, in the following order, separate, overlying light sensitive silver halide emulsion layers, the first overlying light sensitive emulsion layer being sensitive to green radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form a magenta dye, and the second overlying light sensitive emulsion layer being sensitive to red radiation and containing a compound which reacts with oxidized aromatic primary amino color developer to form cyan dye.

References Cited UNITED STATES PATENTS 2,493,748 1/1950 Brooker et a1. 96102 2,519,001 8/1950 Sprague 96102 2,947,628 8/1960 Fierke et al 96102 NORMAN G. TORCHIN, Primary Examiner A. T. SUROPICO, Assistant Examiner US. Cl. X.R. 96-22, 

